The vehicle radios including AM/FM and citizen band radios generally require the installation of an external antenna on a roof, door or fender. In many prior art antenna assemblies, a water leakage path is created wherein water running down the mast may eventually pass through the antenna mount to the inside surface of a body panel to which the antenna assembly is attached. If water reaches the inside of a body panel moisture may accumulate and lead to rust and corrosion of the body panel.
Antenna assemblies normally connected to a radio by a coaxial cable that includes a center conductor that is surrounded by a tubular shield. Generally, the tubular shield is connected to ground on the vehicle while the center conductor is connected directly to the mast of the antenna below the surface of the body panel to which the antenna assembly is to be attached. The shield is normally connected to the vehicle ground while the center connector is connected through an impedance coil to the mast.
Another problem presented by prior art antenna assembly designs is that they are difficult to install. For instance, on a roof mount truck antenna, one or two persons are generally required to hold upper and lower halves of the antenna mount to align and secure the two halves of the antenna mount together. In original equipment installations and after market installations, assembly of the antenna to a vehicle body panel is complicated by the need to, for example, hold the top half of the antenna mount with a wrench while using another wrench to secure the lower half of the antenna assembly to the upper half.
The lower antenna assembly may also require connection of electrical contacts to the vehicle and antenna mast and to a coaxial cable. In multi-part antenna assemblies it may be difficult to hold all of the parts of the lower antenna assembly together while trying to secure it to the upper antenna assembly.
Another problem with prior art antenna assemblies is that the antenna assemblies are normally designed to be assembled together over a body panel having a limited range of thickness. For example, the original equipment antennas may be installed on the roof of a truck prior to assembly of the head liner and may require securing the antenna assembly through one or two thicknesses of sheet metal. If an antenna is added to the truck roof as a retrofit, it may be necessary to secure the antenna assembly through both the roof and head liner greatly increasing the thickness of the body panel to which the antenna assembly must be secured. Previously, an entirely different antenna assembly hardware is provided for OEM and after market installations.
These and other problems and disadvantages associated with the prior art are addressed by this invention.